President Emmanuel Macron says the French government itself fueled homegrown Islamic extremism by abandoning its poorest neighborhoods — and he’s promising tough and “sometimes authoritarian” new measures to combat radicalization.

Macron unveiled a multibillion-euro plan Tuesday to help France’s troubled banlieues — suburban regions where crime flourishes and job opportunities are scant, especially for minorities with origins in former French colonies.

More than 5 million people live in France’s poorest neighborhoods, where unemployment is 25 percent — well above the nearly 10 percent national average. For those under 30, the prospects are even worse — more than a third are officially unemployed.

Macron’s answer is to provide grants for poor youths to launch startups, double the funding for public housing, expand child care, improve public transport in isolated or poor neighborhoods, offer subsidies for companies that hire disadvantaged youth and hire more local police officers.

French President Emmanuel Macron shakes hands with a resident next to French Minister of Public Action and Accounts Gerald Darmanin, second right, during a visit to Tourcoing, Nov. 14, 2017.

Macron’s predecessors also spent billions to try to fix the banlieues, and failed. But he’s undeterred, and says the stakes are increasingly high.

“Radicalization took root because the state checked out” and abdicated its responsibilities in impoverished neighborhoods, Macron said — leaving extremist preachers to fill the void.

Radical recruiters argued “I will take care of your children, I will take care of your parents ... I will propose the help that the nation is no longer offering,” Macron said.

Several extremist attackers who have targeted France in recent years were raised in troubled French social housing. The head of domestic French intelligence agency DGSI, Laurent Nunez, said Tuesday that nearly 18,000 people in France are on radicalism watch lists, a growing number.

Macron said his government will present about 15 measures to fight radicalization and will close “unacceptable structures” that promote extremism and “try to fracture us.”

Macron spent three hours Monday talking to residents in Clichy-sous-Bois, a Paris suburb where the death of two boys fleeing police led to weeks of nationwide riots in 2005, an eruption of anger over discrimination, isolation and joblessness.

French President Emmanuel Macron, center, meets residents of the Cite du Chene Pointu during his visit focused on the theme of urban planing in Clichy-sous-Bois, Nov. 13, 2017.

On Tuesday, he visited Tourcoing in northern France, taking selfies with residents and promoting local technology entrepreneurs.

Labeled by critics as the “president of the rich” for his business-friendly economic vision, Macron insisted Tuesday that his strategy will only succeed if companies hire minorities and the poor.

He promised measures to name and shame companies found to discriminate when hiring, to ensure help for teenagers seeking internships, and to include poor youths in French technology incubators.

Some proposals are small but significant, such as state aid to keep libraries open later, so young people have a safe place to be after dark in dangerous neighborhoods.